301 research outputs found
Ionized and hot molecular outflows in the inner 500 pc of NGC1275
The role of feedback from Active Galactic Nuclei (AGN) in the evolution of
galaxies is still not not fully understood, mostly due to the lack of
observational constraints in the multi-phase gas kinematics on the ten to
hundred parsec scales. We have used the Gemini Near-infrared Integral Field
Spectrograph (NIFS) to map the molecular and ionized gas kinematics in the
inner 900900 pc of the Seyfert galaxy NGC1275 at a spatial
resolution of 70 pc. From the fitting of the CO absorption bandheads in
the K-band, we derive a stellar velocity dispersion of km s,
which implies a black hole mass of
M. We find hot ( K) molecular and ionized outflows with
velocities of up to 2 000 km s and mass outflow rates of
yr and yr,
respectively, in each of these gas phases. The kinetic power of the ionized
outflows corresponds to only 0.05 per cent of the luminosity of the AGN of NGC
1275, indicating that they are not powerful enough to provide significant AGN
feedback, but may be effective in redistributing the gas in the central region
of the galaxy. The AGN driven outflows seem to be responsible for the shocks
necessary to produce the observed H and [Fe II] line emission.Comment: Accepted for publication in MNRA
Designing Behavioral Interventions That Work: The Triple T – Triple R Competing Pathways Model
Increasing numbers of children are entering our nation’s schools with mental or behavioral health problems. Although many of these children are included in general education programs, teachers report feeling under- or unprepared to manage problematic behaviors. This is not surprising given that reviews of teacher training programs have evidenced limited coursework in classroom management. Within this paper, we present a framework, the Triple T – Triple R Competing Pathways Model, that is grounded in the tenets of Applied Behavior Analysis (ABA). ABA has decades of empirical evidence to support its use in the classroom. Triple T – Triple R simplifies the competing pathways chart frequently utilized within ABA, rendering our model accessible to teachers who might not have previous training or experience with application of behavioral tenets
Morphology of AGN Emission Line Regions in SDSS-IV MaNGA Survey
Extended narrow-line regions (NLRs) around active galactic nuclei (AGN) are
shaped by the distribution of gas in the host galaxy and by the geometry of the
circumnuclear obscuration, and thus they can be used to test the AGN
unification model. In this work, we quantify the morphologies of the
narrow-line regions in 308 nearby AGNs (, \lbol
\erg{}) from the MaNGA survey. Based on the narrow-line region maps, we find
that a large fraction (81\%) of these AGN have bi-conical NLR morphology. The
distribution of their measured opening angles suggests that the intrinsic
opening angles of the ionization cones has a mean value of 85--98 with
a finite spread of 39-44 (1-). Our inferred opening angle
distribution implies a number ratio of type I to type II AGN of 1:1.6--2.3,
consistent with other measurements of the type I / type II ratio at low AGN
luminosities. Combining these measurements with the WISE photometry data, we
find that redder mid-IR color (lower effective temperature of dust) corresponds
to stronger and narrower photo-ionized bicones. This relation is in agreement
with the unification model that suggests that the bi-conical narrow-line
regions are shaped by a toroidal dusty structure within a few pc from the AGN.
Furthermore, we find a significant alignment between the minor axis of host
galaxy disks and AGN ionization cones. Together, these findings suggest that
obscuration on both circumnuclear (pc) and galactic ( kpc) scales
are important in shaping and orienting the AGN narrow-line regions.Comment: 14 pages, 7 figures, and 1 table, accepted for publication in MNRA
Optical and mid-infrared neon abundance determinations in star-forming regions
We employed observational spectroscopic data of star-forming regions compiled
from the literature and photoionization models to analyse the neon ionic
abundances obtained using both optical and mid-infrared emission-lines.
Comparing Ne++/H+ ionic abundances from distinct methods, we found that, in
average, the abundances obtained via IR emission-lines are higher than those
obtained via optical lines by a factor of 4. Photoionization models with
abundance variations along the radius of the hypothetical nebula provide a
possible explanation for a large part of the difference between ionic
abundances via optical and infrared emission-lines. Ionization Correction
Factor (ICF) for the neon is obtained from direct determinations of ionic
fractions using infrared emission-lines. A constant Ne/O ratio (logNe/O \approx
-0.70) for a large range of metallicity, independently of the ICF used to
compute the neon total abundance is derived.Comment: 17 pages, 14 figures, accepted by MNRA
Circumnuclear star formation in Mrk 42 mapped with Gemini Near-infrared Integral Field Spectrograph
We present Gemini Near-infrared Integral Field Spectrograph (NIFS)
observations of the inner kpc of the narrow-line Seyfert 1
galaxy Mrk 42 at a spatial resolution of 60 pc and spectral resolution of 40 km
s. The emission-line flux and equivalent width maps clearly show a ring
of circumnuclear star formation regions (CNSFRs) surrounding the nucleus with
radius of 500 pc. The spectra of some of these regions show molecular
absorption features which are probably of CN, TiO or VO, indicating the
presence of massive evolved stars in the thermally pulsing asymptotic giant
branch (TP-AGB) phase. The gas kinematics of the ring is dominated by rotation
in the plane of the galaxy, following the large scale disk geometry, while at
the nucleus an additional outflowing component is detected blueshifted by
300-500 kms, relative to the systemic velocity of the galaxy. Based on
the equivalent width of Br, we find evidences of gradients in the age
of HII regions along the ring of Mrk 42, favoring the pearls on a string
scenario of star formation. The broad component of Pa emission line
presents a Full Width at Half Maximum (FWHM) of 1480 kms, implying
in a mass of ~M for the central supermassive
black hole. Based on emission-line ratios we conclude that besides the active
galactic nucleus, Mrk 42 presents nuclear Starburst activity.Comment: 14 pages, MNRAS accepte
AGN feedback and star formation in the peculiar galaxy NGC 232: Insights from VLT-MUSE Observations
We use VLT-MUSE integral field unit data to study the ionized gas physical
properties and kinematics as well as the stellar populations of the Seyfert 2
galaxy NGC\,232 as an opportunity to understand the role of AGN feedback on
star formation. The data cover a field of view of 6060 arcsec at
a spatial resolution of \,850\,pc. The emission-line profiles have been
fitted with two Gaussian components, one associated to the emission of the gas
in the disc and the other due to a bi-conical outflow. The spectral synthesis
suggests a predominantly old stellar population with ages exceeding 2\,Gyr,
with the largest contributions seen at the nucleus and decreasing outwards.
Meanwhile, the young and intermediate age stellar populations exhibit a
positive gradient with increasing radius and a circum-nuclear star forming ring
with radius of 0.5\,kpc traced by stars younger than 20 Myr, is observed.
This, along with the fact that AGN and SF dominated regions present similar
gaseous oxygen abundances, suggests a shared reservoir feeding both star
formation and the AGN. We have estimated a maximum outflow rate in ionized gas
of 1.26\,M\,yr observed at a distance of 560 pc
from the nucleus. The corresponding maximum kinetic power of the outflow is
erg\,s. This released energy could be sufficient
to suppress star formation within the ionization cone, as evidenced by the
lower star formation rates observed in this region.Comment: 14 pages,10 figures. Submitted to MNRA
Spatially resolved observations of outflows in the radio loud AGN of UGC 8782
We use optical Integral Field Spectroscopy (IFU) to study the gas emission
structure and kinematics in the inner 3.44.9 kpc region of the
galaxy UGC 8782 (3C 293), host of a radio loud Active Galactic Nucleus (AGN).
The observations were performed with the GMOS-IFU on the Gemini North
telescope, resulting in a spatial resolution of pc at the distance of
the galaxy. While the stars present ordered rotation following the orientation
of the large scale disc, the gas shows a disturbed kinematics. The
emission-line profiles present two kinematic components: a narrow
( km s) component associated with the gas in the disc
of the galaxy and a broad ( km s) component produced
by gas outflows. Emission-line ratio diagrams indicate that the gas in the disc
is excited by the AGN radiation field, while the emission of the outflow
includes additional contribution of shock excitation due to the interaction of
the radio jet with the environment gas. Deviations from pure rotation, of up to
30 km s, are observed in the disc component and likely produced by a
previous merger event. The broad component is blueshifted by km
s relative to the systemic velocity of the galaxy in all locations. We
construct radial profiles of the mass outflow rate and kinetic power of the
ionized gas outflows, which have the maximum values at kpc from the
nucleus with peak values of M
yr and (6.81.1)10 erg
s. The kinetic coupling efficiency of these outflows is in the range of
13 per cent, indicating that they could be powerful enough to affect the
star formation in the host galaxy as predicted by theoretical simulations.Comment: Accepted for publication by MNRA
SDSS-IV MaNGA: Identification of active galactic nuclei in optical integral field unit surveys
In this paper, we investigate 2727 galaxies observed by MaNGA as of June 2016
to develop spatially resolved techniques for identifying signatures of active
galactic nuclei (AGN). We identify 303 AGN candidates. The additional spatial
dimension imposes challenges in identifying AGN due to contamination from
diffuse ionized gas, extra-planar gas and photoionization by hot stars. We show
that the combination of spatially-resolved line diagnostic diagrams and
additional cuts on H surface brighness and H equivalent width
can distinguish between AGN-like signatures and high-metallicity galaxies with
LINER-like spectra. Low mass galaxies with high specific star formation rates
are particularly difficult to diagnose and routinely show diagnostic line
ratios outside of the standard star-formation locus. We develop a new
diagnostic -- the distance from the standard diagnostic line in the line-ratios
space -- to evaluate the significance of the deviation from the star-formation
locus. We find 173 galaxies that would not have been selected as AGN candidates
based on single-fibre spectral measurements but exhibit photoionization
signatures suggestive of AGN activity in the MaNGA resolved observations,
underscoring the power of large integral field unit (IFU) surveys. A complete
census of these new AGN candidates is necessary to understand their nature and
probe the complex co-evolution of supermassive black holes and their hosts.Comment: 18 pages, 11 figures, accepted to MNRA
- …